JP5974832B2 - Coil device - Google Patents

Description

  The present invention relates to a coil device that can be suitably used as a relatively large transformer used for, for example, in-vehicle use.

  In a coil device used as a transformer or the like, for example, as shown in Patent Document 1 below, the coil device may be resin-sealed.

  On the other hand, as the core of a coil device used for a relatively large transformer used for in-vehicle applications, etc., it is considered to use an E-type core for reasons of downsizing, noise reduction, cost reduction and workability. Has been.

  However, when an E-type core is used, the mid-leg in the E-type core is caused by concentration of thermal stress due to a difference in heat dissipation between the middle leg of the core and the outer leg of the core, resulting in a temperature difference. The inventors of the present application have found that there is a problem that cracks are likely to occur at the intersection between the base and the base.

JP 2010-267932 A

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a coil device having excellent magnetic properties without causing cracks in the core when used as a relatively large transformer or the like. It is.

In order to achieve the above object, a coil device according to the present invention comprises:
A coil device having an E-type core, a bobbin, and a coil attached to the outer periphery of the bobbin;
The E-type core is
A base that is substantially parallel to a plane including the first axis and the second axis among the first axis, the second axis, and the third axis perpendicular to each other;
A pair of side legs respectively protruding in the third axial direction from both ends of the base along the second axial direction;
A middle leg projecting in the third axial direction from the base between the pair of side legs,
The middle leg and the base are separated by a dividing surface of the divided core so that a pair of the side legs are formed in each of the pair of separated divided cores,
A predetermined gap is formed between the divided surfaces,
The separated middle leg is inserted into a through hole of the bobbin.

  According to the experiments by the present inventors, the local stress generated at the intersection between the middle leg and the base is compared with the case where the conventional E-type core is used by the configuration as described above. It was confirmed that it can be halved to about ½ or less. Therefore, in the coil device according to the present invention, it is possible to effectively suppress the occurrence of cracks and the like even when thermal stress is generated in the core.

  Further, the middle leg and the base in the E-type core are separated by the dividing surface of the dividing core, and since a predetermined gap is formed between the dividing surfaces, heat dissipation is also improved. Furthermore, according to the present invention, the E-type core is configured by combining a pair of split cores each having a simple shape, which facilitates the manufacture of the core and reduces the manufacturing cost. Moreover, since the divided E-type core according to the present invention has the same magnetic field lines as the E-type core as a whole, the magnetic properties of the core are equivalent to those of a general E-type core.

  In the present invention, the predetermined gap is preferably 0.05 to 5 mm, and more preferably 0.1 to 3 mm. These predetermined gaps are not necessarily formed on the entire surface between the split surfaces of the split cores.

  Preferably, at least a lower part of the coil device along the third axis direction is accommodated in the case and is in contact with the heat radiation resin. The heat dissipation of the middle leg is further improved by contacting with the heat dissipation resin.

  Preferably, at least a space between the divided surfaces positioned at the protruding tips of the middle legs is filled with the heat-dissipating resin. In particular, by interposing the heat-dissipating resin at the protruding tip portion of the middle leg, that portion is effectively radiated.

The coil device of the present invention may have a pair of the E-type cores,
Each of the divided middle legs of the pair of E-shaped cores is inserted into the through holes of the bobbin from opposite sides of the third axial direction,
In the middle of the through hole in the third axial direction, the projecting tips of the divided middle legs face each other,
Outside the bobbin, the separated side legs of the pair of E-shaped cores may be butted against each other.

  Thus, even when a pair of E-type cores are used, the present invention is excellent in stress relaxation characteristics and heat dissipation, and also contributes to a reduction in manufacturing cost.

The coil device of the present invention may have the E-type core and the I-type core,
The I-type core is disposed substantially parallel to the base at the end of the bobbin located on the opposite side of the base along the third axis direction with respect to the base in the E-type core,
The projecting tip of the middle leg inserted into the through hole is arranged to face the middle part of the I-type core,
The protruding tips of the side legs formed at both ends of the E-type core may be butted against both ends of the I-type core in the second axial direction.

  As described above, even when the E-type core and the I-type core are used, the present invention is excellent in stress relaxation characteristics and heat dissipation, and contributes to a reduction in manufacturing cost. The I-type core may be separated by a predetermined gap in the intermediate portion.

Preferably, the coil device according to the present invention comprises:
A first bobbin in which a first winding part around which a first wire constituting either one of a primary coil or a secondary coil is wound is formed on the outer periphery;
A second bobbin mounted on the outer periphery of the first bobbin and having a second winding part formed on the outer periphery on which a second wire constituting either the primary coil or the secondary coil is wound; A coil device comprising:
At least one of the first winding portion and the second winding portion includes a plurality of partition walls that separate wires adjacent to each other along the winding axis of the first wire or the second wire. Formed at predetermined intervals along the axis,
The section width along the winding axis in each section separated by the partition wall is set to a width that only one wire can enter,
The height of the partition is set to a height at which one or more of the wires can enter,
Each partition may be formed with at least one communication groove that communicates between adjacent sections.

  In such a coil device, when the wire is wound more than one layer around the winding part in which the partition wall is formed, after winding more than one layer in each section, more than one layer is wound in the adjacent section. Then, the wire is sequentially moved to the adjacent section through the communication groove and wound further. Therefore, the voltage difference between the overlapping wires in each section is small, and the wires adjacent to each other in the winding axis direction are insulated by the partition walls, so that the withstand voltage characteristics between the coils are improved and the high frequency characteristics are improved.

  In addition, since the wire is wound so that only a single wire exists along the winding axis direction in each section, it becomes easy to prevent variations in the winding position of the wire per layer, and leakage. Contributes to stabilization of characteristics. That is, it becomes easy to strictly control the coupling coefficient K between the primary coil and the secondary coil, and the coil device of the present invention can be suitably used as a leakage transformer.

  In addition, the coil device can be used as a vertical type coil device in which the winding axis of the coil is disposed perpendicular to the mounting substrate surface, so that the core inserted in the hollow portion of the first bobbin can be easily cooled. .

Preferably, the first wire disposed on the inner peripheral side is
Configure the secondary coil to operate a high voltage compared to the primary coil,
In the first winding part, a plurality of partition walls are formed along the winding axis.

  In this case, the insulation is facilitated by disposing the secondary coil on which the high voltage acts on the inside of the primary coil on which the relatively low voltage acts. In this case, the second wire may be wound in a normal aligned manner in the second winding part.

  Preferably, the second bobbin can be divided by a dividing line parallel to the winding axis. With this configuration, it is easy to arrange the second bobbin on the outer periphery of the first bobbin.

  The first full width in the winding axis direction of the first winding part may be different from the second full width in the winding axis direction of the second winding part. The leakage characteristics can also be adjusted by making the first full width different from the second full width. The leakage characteristics can also be adjusted by making the first winding part and the second winding part have the same overall width and different numbers of winding layers.

  Preferably, the communication grooves formed in the partition walls are arranged so as to communicate linearly along the winding axis direction. Preferably, two or more communication grooves are formed in each of the partition walls. One of the connecting grooves is used as a movement path between the sections of the wire, and the other is for returning the winding start end or winding end end of the wire to the terminal formed at one end of the winding shaft. Can be used as a return path. If the return path is straight, the end of the wire can be connected to the terminal with the shortest distance.

At least one of the partition walls abuts on the inner peripheral surface of the second bobbin, and the first winding part and the second winding part are positioned substantially concentrically. good. In this case, it is not necessary to separately provide a member for positioning the first bobbin and the second bobbin.
An insulating tape may be wound between the wire winding portion and the wire winding portion wound thereon.

FIG. 1A is a perspective view of a coil device according to an embodiment of the present invention. FIG. 1B is a perspective view of the coil device with the case shown in FIG. 1A removed. FIG. 2 is an exploded perspective view of the coil device shown in FIG. FIG. 3A is a cross-sectional view of a principal part taken along line IIIA-IIIA shown in FIG. 1A. FIG. 3B is a cross-sectional view of the main part along the line IIIB-IIIB shown in FIG. 1A. FIG. 4 is a perspective view of only the core shown in FIG. FIG. 5 is a schematic view showing the relationship between the primary coil and the secondary coil in the coil device shown in FIG. FIG. 6 is a schematic diagram showing the dimensional relationship of the partition walls shown in FIG. FIG. 7 is a schematic view showing a relationship between a primary coil and a secondary coil in a coil device according to another embodiment of the present invention. FIG. 8 is an overall perspective view of the coil device according to the embodiment shown in FIG. FIG. 9A is a schematic diagram illustrating a relationship between a primary coil and a secondary coil in a coil device according to still another embodiment of the present invention. FIG. 9B is a schematic diagram illustrating a relationship between a primary coil and a secondary coil in a coil device according to still another embodiment of the present invention. FIG. 9C is a schematic diagram illustrating a relationship between a primary coil and a secondary coil in a coil device according to still another embodiment of the present invention. FIG. 10 is a cross-sectional view of a main part of a coil device according to another embodiment of the present invention. FIG. 11 is a perspective view of a coil device according to still another embodiment of the present invention. 12 is a schematic cross-sectional view taken along line XII-XII in FIG.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

1 to 4, a coil device 10 according to an embodiment of the present invention includes a pair of E-type cores 12, a first bobbin 40, a second bobbin 50, and a case 90. Have

  The pair of E-shaped cores 12 are assembled to form a magnetic path through which a magnetic flux generated by a coil described later passes. These cores 12 have a symmetrical shape and are connected to each other so as to sandwich the second bobbin 50 and the first bobbin 40 from the vertical direction (Z-axis direction in FIG. 1).

  As shown in FIG. 3A, each of the cores 12 and 12 is a core having a substantially E-shaped longitudinal section (cut surface including the Y axis and the Z axis). Each of the cores 12 and 12 is composed of a ferrite core, and has a flat bases 13 and 13 extending in the Y-axis direction, and a pair of side legs 16 protruding in the Z-axis direction from both ends of the bases 13 and 13 in the Y-axis direction. , 16 and middle legs 14, 14 projecting in the Z-axis direction from intermediate positions in the Y-axis direction of the bases 13, 13.

  In the present embodiment, each core 12 includes a middle leg 14 and a base so that a pair of side legs 16 disposed at both ends in the Y-axis direction are formed on each of the pair of divided cores 12a and 12a. 13 is separated by the split surfaces of the split cores 12a, 12a. A predetermined gap 15 is formed between the divided surfaces 12 b and 12 b, and the separated middle leg 14 is inserted into the first through hole 44 a of the bobbin 40.

  The width t (see FIG. 4) of the gap 15 in the X-axis direction is preferably 0.05 to 5 mm, more preferably 0.1 to 3 mm. If the width t is too small, the effect of the present invention is small, and if the width t is too large, the size tends to be unnecessarily large. Even if the gap 15 is formed, the magnetic characteristics as the E-type core hardly change. This is because there is little change in the flow of magnetic field lines as a whole.

  Further, the predetermined gap 15 is not necessarily formed on the entire surface between the divided surfaces 12b and 12b of the divided cores 12a and 12a, and when the total area between the divided surfaces 12b and 12b is 100%. The predetermined gap 15 may be formed at a rate of 50 to 100%, preferably 80 to 100%. Further, the predetermined gap 15 does not need to be uniform over the entire surface, and may vary within a range of 0 to 5 mm, preferably within a range of 0.1 to 5 mm.

  In the drawings, the Z-axis is the height direction of the coil device 10, and the height of the coil device can be reduced as the height of the coil device 10 in the Z-axis direction becomes shorter. In addition, the Y axis and the X axis are perpendicular to each other and perpendicular to the Z axis. In this embodiment, the X axis coincides with the longitudinal direction of the bobbins 40 and 50 and is substantially parallel to the divided surfaces 12b and 12b. And the Y axis is substantially perpendicular to the divided surfaces 12b and 12b.

  However, in the present invention, the dividing surfaces 12b and 12b are not necessarily flat and may be curved surfaces. The dividing surfaces 12b and 12b are not necessarily parallel to the X axis, and may be inclined at a predetermined angle, or may be zigzag or corrugated along the X axis. In any case, the gap width t in the dividing direction between the dividing surfaces 12b and 12b has the relationship described above.

  As shown in FIG. 2, the first bobbin 40 includes a first bobbin substrate 42 having a substantially rectangular flat plate shape. As shown in FIGS. 3A and 3B, a first hollow cylindrical portion 44 is integrally formed at a substantially central portion of the first bobbin substrate 42 so as to extend upward in the Z-axis direction.

  As shown in FIG. 2, the first bobbin upper collar portion 48 is integrated with the upper portion of the first hollow tube portion 44 in the Z-axis direction so as to protrude radially from the first hollow tube portion 44 in the Y-axis-X axis plane. Molded. Terminal block portions 49 are integrally formed at the four corners of the first bobbin upper collar portion 48, and a pair of first terminals 70 and 72 can be detachably mounted. Of course, these terminals 70 and 72 may be integrally formed with the bobbin 40.

  These terminals 70 and 72 are made of, for example, metal terminals. As will be described later, the first terminal 70 has a lead portion 22a (see FIGS. 1 and 2) of the first wire 22 constituting the inner coil 20 serving as a secondary coil. 3B) is connected via the solder portion 24, and the lead portion 32a (see FIG. 1) of the second wire 32 constituting the outer coil 30 serving as the primary coil is connected to the second terminal 72 via the solder portion 34. Connected.

  As shown in FIGS. 2, 3, and 5, a first winding portion 45 is provided on the outer periphery of the first hollow cylinder portion 44 located between the first bobbin upper collar portion 48 and the first bobbin substrate 42. It is formed. In the first winding part 45, a plurality of partition walls 46 separating wires adjacent to each other along the winding axis (Z-axis) of the first wire 20 are arranged at predetermined intervals along the winding axis. The first hollow cylinder portion 44 is formed integrally with the upper collar portion 48 in parallel. Details of the partition 46 and the method of winding the first wire will be described later.

  The first bobbin substrate 42, the first hollow tube portion 44, the first bobbin upper collar portion 48, the terminal block portion 49, and the partition wall 46 in the first bobbin 40 are preferably integrally formed by injection molding or the like.

  A first through hole 44 a that penetrates in the Z-axis direction is formed in the first hollow cylinder portion 44 of the first bobbin substrate 42. The divided middle leg 14 in the core 12 enters the first through hole 44a from above and below in the Z-axis direction, and the front end 18 of the middle leg 14 is abutted at a substantially central portion in the Z-axis direction of the through hole 44a. It has become.

  As shown in FIG. 2, the second bobbin 50 is combined with a dividing line 51 parallel to the winding axis (Z axis) and can be divided into two, and the second winding portion 55 is formed on the outer periphery. It is. In FIG. 2, the coils 20 and 30 are not shown. The second bobbin 50 is mounted on the outer periphery of the first bobbin 40 after the first wire 22 is wound around the first winding portion of the first bobbin 40 to form the inner coil 20, and is combined at the dividing line 51. It is.

  The second bobbin 50 has a second hollow cylinder part 54 that covers the inner coil 20 from the outside. Are formed along the circumferential direction at predetermined intervals in the Z-axis direction. The lower collar part 52 and the upper collar part 58 are provided in parallel to the plane of the XY axis and extend in parallel to the installation surface.

Between the lower collar portion 52 and the upper collar portion 58 is a second winding portion 55, and the second winding portion 55 constitutes the outer coil 30 serving as a primary coil as shown in FIG. The second wire 32 (32 _{1 to} 32 _n ) is aligned and wound. The aligned-winding, the first layer is a winding of the second layer is wound from the wound, so that the overlap with the wires 32 _n of winding end further eye winding start wire 32 ₁ and the second layer.

  In the present embodiment, by changing the formation position and the formation interval of the upper collar part 52 and the lower collar part 58 formed on the outer periphery of the second hollow cylinder part 54 in the second bobbin 50, as shown in FIG. Compared to the first full width L1 of the first winding part 45 in the winding axis direction, the second full width L2 of the second winding part 55 in the winding axis direction can be shortened.

  As shown in FIGS. 2 and 3A, a pair of insulating cover members 60 are attached to the outer periphery of the second winding portion 55 of the second bobbin 50 to which the outer coil 30 is attached from both sides in the Y-axis direction. . The insulating cover member 60 is made of, for example, synthetic resin, and an outer peripheral surface thereof serves as a guide surface for guiding the side legs 16 in the core 12, and the outer coil 30 is located on the inner peripheral surface thereof.

  As shown in FIG. 2, lead insertion notches 58 a are formed at two positions in the circumferential direction of the upper collar portion 58 in the second bobbin 50 at positions corresponding to the second terminals 72. As shown in FIG. 1B, the lead portion 32a that is the winding start end and the winding end end of the second wire 32 is passed through the notch 58a, and is connected to the second terminal 72 at each solder portion.

  As shown in FIG. 2, each of the two-divided second bobbins 50 including the flange portions 52 and 58 and the second hollow cylinder portion 54 is integrally formed by injection molding or the like. The cover member 60 can also be formed by injection molding or the like.

As shown in FIGS. 5 and 6, in this embodiment, compartment width w1 along the winding axis of each compartment 47 which are separated by the partition wall 46 (Z-axis), only one wire 22 (22 ₁ ˜22 _n ) is set to a width that can enter. That is, the partition width w1 is preferably in a relationship of w1 <(2 × d1) with respect to the wire diameter d1 of the wire 22. If the section width w1 is too wide with respect to the wire diameter d1, it is difficult to wind only one section in the winding axis direction with respect to each section 47.

  The height h1 of each partition wall 46 is preferably greater than m × d1, where m is the total number of cells that are scheduled to be wound around each section 47. In that case, as shown in FIGS. 3A and 3B, the top of the partition wall 46 is brought into contact with the inner peripheral surface of the second bobbin 50, and the first winding part 45 and the second winding part 55 are substantially omitted. Positioning can be performed concentrically, and there is no need to separately provide a member for positioning the first bobbin 40 and the second bobbin 50.

  The tops of all the partition walls 46 do not have to be brought into contact with the inner peripheral surface of the second bobbin 50. The length of any one, preferably two or more partition walls separated in the winding axis direction, It may be set longer than the partition walls, and only the tops of the partition walls may be positioned so as to contact the inner peripheral surface of the second bobbin 50. Alternatively, the positioning of the first bobbin 40 and the second bobbin 50 may be performed by a member other than the partition wall 46.

  In such a case, as indicated by the dotted line in FIG. 6, the height h1 of the partition wall 46 may be smaller than m × d1. However, the length Δh (= m × d1−h1) of the protruding portion is preferably smaller than d1 / 2 so that the wire 22 does not move to the adjacent section 47. Further, it is preferable that the protruding height of the first bobbin substrate 42 and the flange portion 48 is higher than the height of the partition wall 46.

  The first wire 22 may be composed of a single wire or a stranded wire, and is preferably composed of an insulation coated conductor. The outer diameter d1 of the wire 22 is not particularly limited, but when a large current is passed, for example, φ1.0 to φ3.0 mm is preferable. The second wire 32 may be the same as the first wire 22, but may be different.

  In this embodiment, the first wire 22 is thicker than the second wire 32 because a high voltage is applied to form a secondary coil of the transformer. Is not particularly limited, and the wire diameter may be the same or may be different. The materials of the first wire 22 and the second wire 32 may be the same or different.

As shown in FIG. 5, in this embodiment, the first bobbin 40, a first wire 22 ₍₂₂ 1 through 22 _n) is, for example, Volume 2 from the compartment 47 located at the bottom of the Z-axis direction (22 ₁ 22 ₂₎ wound in, the next, the partition 47 located thereon, Volume 3 th wire 22 ₃ is wound. In the same manner, the winding end 22 _n of the first wire 22 will be located in a compartment 47 located at the top of the farthest Z-axis direction from the wire 22 ₁ at the winding start.

On the other hand, as described above, in the second bobbin 50, the second wire 32 (32 _{1 to} 32 _n ) constituting the outer coil 30 serving as the primary coil is aligned and wound around the second winding portion 55. The The aligned-winding, the first layer is a winding of the second layer is wound from the wound, so that the overlap with the wires 32 _n of winding end further eye winding start wire 32 ₁ and the second layer.

  As shown in FIGS. 1 and 2, in the first bobbin 40, a pair of connecting grooves 46a extending linearly in the Z-axis direction are formed on both sides in the X-axis direction of the partition walls 46 that are continuous in the circumferential direction. It is. One of the pair of communication grooves 46a is used to move the wire 22 between adjacent sections 47 as shown in FIG. 3B. The other one of the pair of connecting grooves 46 a is used to guide the lead portion 22 a of the wire 22 that is the beginning or end of winding in the direction of the solder portion 24 of the terminal 70.

  The coil device 10 according to the present embodiment is manufactured by assembling the members shown in FIG. 2 and winding a wire around the first bobbin 40 and the second bobbin 50, as shown in FIGS. 1A, 3A, and 3B. As described above, the upper portion in the Z-axis direction including the terminals 70 and 72 is accommodated in the case 90 so as to be exposed. The case 90 is filled with a heat radiating resin 92. The heat-dissipating resin 92 is not particularly limited, but is preferably a resin having excellent heat dissipation, for example, having a thermal conductivity of 0.5 to 5, preferably 1 to 3 W / m · K.

  Examples of the resin excellent in heat dissipation include silicone resin, urethane resin, and epoxy resin, among which silicone resin and urethane resin are preferable. Moreover, in order to improve heat dissipation, the resin may be filled with a filler having high thermal conductivity.

  Further, the heat radiation resin 92 of the present embodiment has a Shore A hardness of 100 or less, preferably 60 or less. This is because even if the core 12 is deformed by heat, the deformation is absorbed and excessive stress is not generated in the core 12. An example of such a resin is a potting resin.

  A cooling device such as a cooling pipe or a cooling fin may be attached below the case 90 via a metal plate or the like.

  Below, an example of the manufacturing method of the coil apparatus 10 is demonstrated using FIG. In manufacturing the coil device 10, first, the first bobbin 40 to which the first terminal 70 and the second terminal 72 are attached is prepared. Although the material of the 1st bobbin 40 is not specifically limited, The 1st bobbin 40 is formed with insulating materials, such as resin.

  Next, the first wire 22 is wound around the outer periphery of the first hollow cylinder portion 44 of the first bobbin 40 to form the inner coil 20. Although it does not specifically limit as the 1st wire 22 used for formation of the inner coil 20, A litz wire etc. are used suitably. In addition, the lead portion 22a, which is the end portion of the first wire 22 when forming the inner coil 20, is entangled with a part of the first terminal 70 and soldered and connected.

  Next, the 2nd bobbin 50 is attached with respect to the 1st bobbin 40 in which the inner side coil 20 was formed. A second wire 32 constituting the outer coil 30 is wound around the outer periphery of the second hollow cylinder portion 54 in the second bobbin 50.

  After that, the covers 60 are attached to both sides of the second bobbin 50 in the Y-axis direction, and then the cores 12 each composed of the split cores 12a and 12a are attached from the vertical direction in the Z-axis direction. That is, the front ends 18 of the divided middle legs 14 and 14 of the core 12 and the front ends 19 of the side legs 16 and 16 are abutted. A gap may be provided between the tips 18 of the middle legs 14 and 14.

  Examples of the material of each core 12 include soft magnetic materials such as metal and ferrite, but are not particularly limited. The core 12 is fixed to the second bobbin 50 and the first bobbin 40 by being bonded using an adhesive or by winding the outer periphery with a tape-shaped member 80. However, the divided cores 12a and 12a are fixed to the second bobbin 50 and the first bobbin 40 so that the gap width t between the divided surfaces 12b and 12b shown in FIG. 4 is maintained within a predetermined range. The

  In this embodiment, the varnish impregnation process may be performed with respect to the coil apparatus 10 after a series of assembly processes. The coil device 10 according to the present embodiment can be manufactured through the steps as described above.

  Thereafter, as shown in FIGS. 1A, 3A, and 3B, the coil device 10 includes the case 90 filled with the heat-dissipating resin 92 so that the upper portion in the Z-axis direction including the terminals 70 and 72 is exposed. Housed inside. The resin 92 may be filled before or after the coil device 10 is accommodated in the case 90. In any case, the resin 92 is also filled in at least a part of the gap 15 between the divided surfaces 12b, and preferably, more than the tips 18 of the middle legs 14, 14 and the tips 19 of the side legs 16, 16 The gap 15 is filled with the resin 92 up to the upper position in the Z-axis direction.

  In particular, at the position between the tips 18 of the middle legs 14, 14, heat is easily trapped, and there is a gap 15 in that part, and heat radiation resin is present in that part, so that the heat inside the middle leg 14 can be reduced. Heat is transferred downward in the Z-axis direction, and heat is easily radiated through the case 90. The case 90 may be made of a metal having excellent heat dissipation or the like, or may be made of resin and cooled by a cooling means that is mounted below the Z-axis direction.

  In the coil device 10 of the present embodiment, the middle leg 14 and the base 13 are divided from the divided cores 12a and 12a so that the pair of side legs 16 are formed on the separated pair of divided cores 12a and 12a, respectively. The surfaces 12b and 12b are separated. In addition, a predetermined gap 15 is formed between the divided surfaces 12 a and 12 a, and the separated middle leg 14 is inserted into the through hole 44 a of the bobbin 40.

  In the present embodiment, the local stress generated at the intersection between the middle leg 14 and the base 13 is reduced to about 1/2, compared to the case where the conventional E-type core is used. Can be halved to about 2 or less. Therefore, in the coil device 10 according to the present embodiment, it is possible to effectively suppress the occurrence of cracks and the like even when thermal stress occurs in the cores 12 and 12.

  In particular, as shown in FIG. 4, when a pair of E-shaped cores 12 are combined, the length Ly in the Y-axis direction is 50 mm or more, the length Lx in the X-axis direction is 20 mm or more, and the length in the Z-axis direction. The use of a large core having an Lz of 10 mm or more is being studied. Conventionally, such a large core has been difficult to use because the thermal stress is particularly large and cracks are generated. In the present embodiment, by providing the gap 15, Since the local stress generated at the intersection with 13 can be halved to about ½ or less of the conventional value, it can be used.

  Further, the middle leg 14 and the base 13 in the E-type core are separated by the divided surfaces 12b and 12b of the divided cores 12a and 12a, and a predetermined gap 15 is formed between the divided surfaces 12a and 12a. Therefore, heat dissipation is also improved. Furthermore, in the present embodiment, the E-type cores 12 and 12 are configured by combining a pair of split cores 12a and 12a each having a simple shape, which facilitates the manufacture of the cores 12 and 12 and reduces the manufacturing cost. Reduction can also be achieved. Each divided core 12a has a U-shaped cross section and is easy to mold. In addition, since the divided E-type cores 12 and 12 according to the present embodiment have the same magnetic field lines as the E-type core as a whole, the magnetic characteristics of the cores 12 and 12 are generally E-type cores. Is equivalent to

  In the present embodiment, at least the lower part of the coil device 10 along the Z-axis direction is accommodated in the case 90 and is in contact with the heat radiation resin 92. By contacting the heat-dissipating resin 92, heat dissipation is further improved.

  Moreover, in the present embodiment, the heat radiation resin 32 is filled between the divided surfaces 12b and 12b located at the protruding tip 18 of the middle leg 14. In particular, since heat is easily trapped at the protruding tip 18 portion of the middle leg 14, the heat dissipation resin 92 is interposed at that portion, so that the portion is effectively radiated.

  The coil device 10 of the present embodiment has a pair of E-type cores 12 and 12, and each of the middle legs 14 into which the pair of E-type cores 12 and 12 are divided is inserted into the through-hole 44 a of the bobbin 40. Inserted from opposite sides in the Z-axis direction. Moreover, in the middle of the through hole 44a in the Z-axis direction, the projecting tips 18 of the divided middle legs 14 face each other, and outside the bobbin 50, the separated side legs 16 of the pair of E-type cores 12 are They are faced with each other. Thus, even when a pair of E-type cores 12 and 12 are used, the present embodiment is excellent in stress relaxation characteristics and heat dissipation, and contributes to a reduction in manufacturing cost.

  In addition, the coil device 10 of the present embodiment is a vertical type in which the Z-axis direction (direction in which the magnetic flux flows) of the middle leg 14 is perpendicular to the installation surface (the lower surface of the case 90). In the coil device 10 which is a vertical type, the bases 13 and 13 of the core 12 are arranged in the vertical direction of the Z axis of the coils 20 and 30, and these bases 13 and 13 have an effect of suppressing leakage magnetic flux in the vertical direction. Therefore, the coil device 10 can effectively suppress the leakage magnetic flux in the vertical direction of the coil device 10 as compared with the horizontal type in which the vertical direction of the coil is hardly shielded by the core.

  The tape-shaped member 80 is mainly used for fixing the core 12. The tape-shaped member 80 is made of a material such as polyester, polyimide, or paper. In the case where the tape-shaped member 80 is also provided with heat dissipation properties, the tape-shaped member 80 is preferably made of a material that is more excellent in thermal conductivity than the core 12, and specifically, for example, aluminum, copper, or the like. It is comprised with the material excellent in thermal conductivity, such as a metal or these alloys. Of course, as the tape-shaped member 80, the tape-shaped members made of the various materials described above may be used in combination.

  In the present embodiment, the bases 13 and 13 and the side legs 16 and 16 of the core 12 cover the combination of the first bobbin 40 and the second bobbin 50 from the outside. With such a structure, leakage magnetic flux can be prevented. The width along the X-axis direction of the bases 12 and 12 and the side legs 16 and 16 may be the same or different with respect to the length along the X-axis direction of the middle legs 14 and 14 of the core 12. By making them substantially the same, the leakage characteristics can be easily adjusted.

  In the coil device 10 according to the present embodiment, as shown in FIG. 5, when the first wire 22 is wound more than one layer around the first winding portion 45 where the partition wall 46 is formed, After winding more than one layer, in the adjacent section 47, more than one layer is wound. Then, as shown in FIG. 2, the wire 22 is sequentially moved to the adjacent section 47 through the connecting groove 46a and wound further. Therefore, as shown in FIG. 5, the winding order of the overlapping first wires 22 in each section 47 is close, the voltage difference between them is small, and the wires adjacent in the winding axis (Z-axis) direction are insulated from each other by the partition wall 46. Thus, the withstand voltage characteristics are improved and the high frequency characteristics are improved.

Moreover, in each section 47, since the wires 22 are wound so that only the single wires 22 _{1 to} 22 _n exist along the winding axis direction, variations in the number of turns of the wires 22 per layer are prevented. This contributes to the stabilization of the leakage characteristics. That is, it becomes easy to strictly control the coupling coefficient K between the outer coil 30 constituting the primary coil and the inner coil 20 constituting the secondary coil, and the coil device 10 of the present embodiment is also suitable as a leakage transformer. Can be used.

  Further, the coil device 10 of the present embodiment can be used as a vertical type coil device in which the winding axis of the coil is disposed perpendicular to the mounting substrate surface (the lower surface of the case 90), and therefore the first bobbin 40 It is easy to cool the core 12 inserted into the hollow portion.

  Moreover, in the present embodiment, the first wire 20 arranged on the inner peripheral side constitutes a secondary coil (inner coil 20) on which a higher voltage acts than the primary coil of the transformer. For this reason, insulation becomes easy by arrange | positioning the secondary coil (inner coil 20) to which a high voltage acts inside the primary coil (outer coil 30) to which a relatively low voltage acts. Further, in the second winding portion 55, the second wire 32 is normally aligned and wound. However, since the second wire 32 is the outer coil 30 serving as a primary coil to which a relatively low voltage is applied, there is a problem. There is no.

  Furthermore, in this embodiment, since the 2nd bobbin 50 can be divided | segmented by the dividing line 51 parallel to a winding axis | shaft, as shown in FIG. 2, the 2nd bobbin 50 is easily put on the outer periphery of the 1st bobbin 40. Can be arranged.

  In the present embodiment, as shown in FIG. 5, the first full width L1 in the winding axis direction of the first winding part 45 is different from the second full width L2 in the winding axis direction of the second winding part 55. Therefore, the leakage characteristics can be adjusted easily and accurately.

  Furthermore, in the present invention, the communication grooves 46a formed in the partition walls 46 are not necessarily arranged on a straight line along the winding axis direction, but preferably communicate in a straight line as shown in FIG. It is arranged as follows. In particular, if the connecting groove 46a serving as the return path of the lead portion 22a is linear in the Z-axis direction, the end portion of the lead portion 22a of the wire 22 can be connected to the terminal 70 at the shortest distance. Further, by forming the connecting groove 46a for moving the wire 22 from each section 47 to the adjacent section 47 in each partition wall 46 at the same position in the circumferential direction, the winding process of the wire 22 is facilitated.

Second Embodiment The coil device 10a according to the second embodiment shown in FIGS. 7 and 8 differs from the coil device according to the first embodiment shown in FIGS. 1 to 6 in the structure of the second bobbin 50a. This is the same as the others, and different parts will be described below.

In this coil device 10a, one or more partition walls 56 are formed in the middle of the winding axis direction of the second bobbin, and the second winding portion 55 is divided into two or more sections 57 along the winding axis direction. It is divided into In each section 57, second wires 32 _{1 to} 32 _k and 32 _{k + 1 to} 32 _n ) are wound in an aligned manner. The partition wall 56 is formed with one or more communication grooves 56a along the circumferential direction. The communication groove 56a has the same function as the communication groove 46a.

  In the coil device 10a of this embodiment, the outer coil 30 constituting the primary coil can be divided and arranged. In addition, the primary coil divided | segmented and arrange | positioned for every division 57 may be a separate independent coil comprised with a different wire, respectively.

Third Embodiment In the first embodiment, as shown in FIG. 5, the center position of the second winding portion 55 in the winding axis direction is aligned with the center of the first winding portion 45 in the winding axis direction. However, not only that, but may be configured as shown in FIG. 9A. In the coil device 10b according to this embodiment, the lower end of the second winding part 55 may be aligned with the lower end position of the first winding part 45 in the winding axis direction.

By doing in this way, it can be expected that the heat radiation effect from the coils 20 and 30 is enhanced. This is because the heat transfer characteristics from not only the coil 20 but also the coil 30 are improved by providing the heat radiating portion at the lower end of the coil device 10b. In the embodiment shown in FIG. 9A, the first wire 22 (22 _{1 to} 22 _n ) is started to be wound from the upper end of the winding shaft. Other configurations and operational effects are the same as those of the coil device according to the first embodiment.

  Further, as in the coil device 10c shown in FIG. 9B, the leakage characteristics can be adjusted by making the first winding part 45 and the second winding part 55 have the same overall width and different numbers of winding layers. Also good. The coil device 10c shown in FIG. 9B is different from the coil device according to the first embodiment shown in FIGS. 1 to 6 in that the length of the second bobbin 50c in the winding axis direction is different, and the winding of the second wire 32 is performed. Only the number of layers is different, and the others are the same.

Further, in the coil device 10d shown in FIG. 9C, the first bobbin 40a is formed on the first winding portion 45 with the first wire 22 (22 _{1 to} 22 _n ) being aligned winding without forming the partition wall 46. The inner coil 20a may be a primary coil in a transformer. In that case, a partition wall 56d similar to the partition wall 46 in the first embodiment is formed in the second winding portion 55 of the second bobbin 50d, and the second wire 32 (32 _{1 to} 32 _n) constituting the outer coil 30d. The same winding method as that of the first wire 22 in the first embodiment is adopted. In this embodiment, the outer coil 30d constitutes a secondary coil of the transformer. Other configurations and operational effects are the same as those of the first embodiment.

  In the above-described embodiment, the outer coil 30 and the inner coil 20 do not have to be positioned concentrically, and may be shifted in order to adjust the leakage characteristics.

Fourth Embodiment As shown in FIG. 10, the coil device 10 e of this embodiment has an E-type core 12 </ b> A and an I-type core 17. The E-shaped core 12A is a core having a substantially E-shaped longitudinal section (cut surface including the Y-axis and the Z-axis). The core 12A includes a flat base 13a extending in the Y-axis direction, a pair of side legs 16a and 16a protruding in the Z-axis direction from both ends of the base 13a in the Y-axis direction, and an intermediate position of the base 13a in the Y-axis direction. And a middle leg 14a protruding in the Z-axis direction.

  In the present embodiment, the core 12A includes the middle leg 14a and the pair of side legs 16a and 16a disposed at both ends in the Y-axis direction so that the pair of divided cores 12a1 and 12a1 are respectively formed. The base 13a is separated by divided surfaces 12b and 12b of the divided cores 12a1 and 12a1. A predetermined gap 15 is formed between the divided surfaces 12 b and 12 b, and the separated middle leg 14 is inserted into the first through hole 44 a of the bobbin 40.

  The I-type core 17 extending linearly in the Y-axis direction is composed of split cores 17a and 17a that are divided into two by split surfaces 17b and 17b formed at substantially the center in the Y-axis direction. The dividing surfaces 17b and 17b are formed at substantially the same position in the Y-axis direction as the dividing surfaces 12b and 12b, and have the same gap width as that in the first embodiment.

  The I-type core 17 is disposed substantially parallel to the base 13a at the end of the bobbin 40 located on the opposite side of the base 13a along the Z-axis direction with respect to the base 13a in the E-type core 12A. The protruding tip 18a of the middle leg 14a inserted into the through hole 44a of the bobbin 40 extends to the same level as the lower end surface of the through hole 44a in the Z-axis direction. It is arranged so as to face each other. Further, the protruding tips 19a of the side legs 16a formed at both ends of the E-type core 12A are butted against both ends of the I-type core 17 in the Y-axis direction.

  As described above, even when the E-type core 12A and the I-type core 17 are used, the present embodiment is excellent in stress relaxation characteristics and heat dissipation, and contributes to a reduction in manufacturing cost. As shown in FIG. 10, the I-type core 17 may be separated by a predetermined gap in the middle part in the Y-axis direction. However, the I-type core 17 extends in the Y-axis direction without being separated. It may be.

  The I-type core is preferably disposed below the Z-axis direction in the coil device 10e. By arranging in this way, the protruding tip 18a of the middle leg 14a in the E-type core 12A is arranged on the lower side of the case 90 in the Z-axis direction. Therefore, the portion where the temperature is likely to rise is disposed below the case 90, and the gap 15 is reliably filled with the heat radiation resin, further improving the heat dissipation. This is because the cooling means is mounted below the case 90. Other configurations and operational effects are the same as those of the coil device according to the first embodiment.

Fifth Embodiment As shown in FIGS. 11 and 12, in the coil device 10f of this embodiment, the inside of the first hollow cylinder portion 44 constituting the first through hole 44a of the bobbin 40 in which the through hole 44a is formed. Positioning convex portions 41 are integrally formed on the peripheral wall at four positions at both ends in the Z-axis direction at both ends in the Y-axis direction. The thickness of the positioning convex portion 41 in the Y-axis direction is the same as the gap width t shown in FIG. 4, and the convex portion 41 is for ensuring the gap width t.

  By inserting the middle leg 14 of the split core 12a into the through hole 44a from above and below in the Z-axis direction so that the convex portion 41 is sandwiched from the Y-axis direction, the split surfaces 12b of the split core 12a are mutually connected to the convex portion 41. The separated state is maintained with a predetermined gap width t corresponding to the thickness in the Y-axis direction. A plurality of convex portions 41 may be formed intermittently in the Z-axis direction on the inner peripheral wall of the first hollow cylindrical portion 44 constituting the first through hole 44a of the bobbin 40, or continuously in the Z-axis direction. It may be formed. Other configurations and operational effects are the same as those of the coil device according to the first embodiment.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  For example, in the above-described embodiment, the plurality of partition walls 46, 56, and 56d that separate the wires adjacent to each other along the winding axis of the first wire 22 or the second wire 32 have a predetermined interval along the winding axis. In the present invention, the partition wall is not necessarily required. That is, in the present invention, the winding method of the first wire 22 and the second wire 32 is not particularly limited, and both may be a normal winding method that does not require a partition wall.

  In the coil device according to the present invention, the case 90 filled with the heat-dissipating resin 92 is not always necessary.

DESCRIPTION OF SYMBOLS 10, 10a-10f ... Coil apparatus 12, 12A ... E type | mold core 12a ... Divided core 12b ... Divided surface 13 ... Base 14 ... Middle leg 15 ... Gap 16 ... Side leg 17 ... I-type core 17a ... Divided core 17b ... Divided surface 18,19,18a, 19a ... front end 20, 20a ... inner coil 22 ₍₂₂ 1 ~22 _n) ... first wire 22a ... leads 24 ... solder portion 30 ... outer coil _{32 (32 1 ~32 k, 32} k + 1 ~ 32 _n ) ... second wire 32a ... lead part 34 ... solder part 40 ... first bobbin 42 ... first bobbin substrate 44 ... first hollow cylinder part 44a ... first through hole 45 ... first winding part 46 ... partition wall 46a ... Communication groove 47 ... Division 48 ... First bobbin upper collar part 50 ... Second bobbin 52 ... Second bobbin lower collar part 54 ... Second hollow cylinder part 55 ... Second winding part 56, 56d ... Partition wall 56a ... Communication Groove 57d ... partition 58 ... second bobbin upper collar 60 ... cover 70 ... first terminal 72 ... second terminal 80 ... tape-like member 90 ... case 92 ... heat radiation resin

Claims (6)

A coil device having an E-type core, a bobbin, and a coil attached to the outer periphery of the bobbin;
The E-type core is
A base that is substantially parallel to a plane including the first axis and the second axis among the first axis, the second axis, and the third axis perpendicular to each other;
A pair of side legs respectively protruding in the third axial direction from both ends of the base along the second axial direction;
A middle leg projecting in the third axial direction from the base between the pair of side legs,
The middle leg and the base are separated by a dividing surface of the divided core so that a pair of the side legs are formed in each of the pair of separated divided cores,
A predetermined gap is formed between the divided surfaces,
The separated middle leg is inserted into the through hole of the bobbin ;
A coil device , wherein a positioning convex portion for securing a width of the gap is formed on an inner peripheral wall of a hollow cylindrical portion constituting the through hole of the bobbin .   The coil device according to claim 1, wherein at least a lower part of the coil device along the third axial direction is accommodated in a case and is in contact with a heat radiation resin.   3. The coil device according to claim 2, wherein the heat-dissipating resin is filled at least between the divided surfaces located at the protruding tips of the middle legs. A pair of the E-shaped cores;
Each of the divided middle legs of the pair of E-shaped cores is inserted into the through holes of the bobbin from opposite sides of the third axial direction,
In the middle of the through hole in the third axial direction, the projecting tips of the divided middle legs face each other,
The coil device according to any one of claims 1 to 3, wherein the separated side legs of the pair of E-shaped cores are butted against each other outside the bobbin. The E-type core and the I-type core;
The I-type core is disposed substantially parallel to the base at the end of the bobbin located on the opposite side of the base along the third axis direction with respect to the base in the E-type core,
The projecting tip of the middle leg inserted into the through hole is arranged to face the middle part of the I-type core,
The coil device according to any one of claims 1 to 3, wherein projecting tips of side legs formed at both ends of the E-type core are abutted against both ends of the I-type core in the second axial direction. .   The coil apparatus according to claim 5, wherein the I-type core is separated at a predetermined gap in the intermediate portion.

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